package com.text.day3_3;

import java.util.HashMap;
import java.util.Properties;

public class MapDemo {
    public static void main(String[] args) {
//        Properties properties = System.getProperties();      这是一个MAP集合
//        properties.forEach((k,v) -> System.out.println(k + "" + v));
        HashMap<Object, Object> hashMap = new HashMap<>();
    }
}
